Subliminal information can trigger the placebo effect and its opposite, the nocebo effect, researchers say.

The finding suggests that patients with certain ailments may feel better or worse depending on subtle cues their brains pick up from the environment, but which they are not consciously aware of.

The placebo effect is the curious biological mechanism whereby patients’ symptoms improve when they take fake medicines with no active ingredient, such as sugar pills or saline injections. It also boosts the effectiveness of genuine medicines.

“This means that our behaviour and emotional experiences are often guided by stimuli out of our consciousness. Once again, the placebo response is emerging as an excellent model to understand how our brain works and how mental events interact with neural events.”

Tip: Guardian Science

The participants looked at faces and experienced an associated heat sensation at varying degrees. Reports of pain correlated with certain faces. But the reports also correlated with faces that seen in a time frame too short for the brain to consciously discern it.

I’ll withhold judgement on this cause it’s a bit of a whopper. I’m FULL of questions about it. The publication source is top notch but I am looking at the media version of the story. Even if I did read the study, I’m not sure I would grasp its full implications. It IS only 40 participants, however. Any time a study contains such a small number (N value), it can’t be considered definitive by any means. Be on the lookout for expert critique of this one.

Here, we performed two experiments in which the responses to thermal pain stimuli were assessed. The first experiment assessed whether a conditioning paradigm, using clearly visible cues for high and low pain, could induce placebo and nocebo responses. The second experiment, in a separate group of subjects, assessed whether conditioned placebo and nocebo responses could be triggered in response to nonconscious (masked) exposures to the same cues.

Mobility is a bad example — I know this from experience with my elderly mother. She has spinal stenosis, but up until recently, has at least been able to get around using a cane, or a walker. However, when the pain is most severe, she also has less mobility. In other words, they are linked.

The links can be complex — pain can cause depression, it can affect appetite, sleep, and so on, all of which can have a real physiological impact. Don’t get me wrong — I’m glad she’s getting real medication for her pain that actually works (when she takes it, that is). But a visit from her grandkids can be a very effective placebo as well.